uPVC windows are made by extruding a rigid, unplasticised polyvinyl chloride (PVC-U) compound into hollow, multi-chamber profiles, cutting and mitring those profiles to size, inserting galvanised steel reinforcement, fusion-welding the corners into a sealed frame, and finally fitting glazing, gaskets, drainage and hardware. In short, the process converts a powder-based plastic compound into a dimensionally stable, weather-sealed window through a controlled sequence of compounding, extrusion, fabrication and assembly.
The term 'uPVC' means the PVC is unplasticised, so it stays rigid rather than flexible like the PVC used in cables or hoses. Modern compounds are lead-free (calcium-zinc stabilised) and UV-stabilised with titanium dioxide, which is what allows finished windows to withstand years of harsh sun, heat and monsoon humidity in climates like Hyderabad, Secunderabad and across Telangana and Andhra Pradesh without warping, fading badly or corroding.
This guide walks through every stage of manufacture, the international and Indian standards that separate a good window from a cheap one, indicative INR pricing, and how the quality of glazing and hardware affects the finished product. If you are comparing suppliers, understanding the process makes it far easier to judge whether a quoted uPVC window is genuinely well built or simply cheap. You can also get a free quote for a specification tailored to your project, or see completed installations among our recent projects.
Step 1: Compounding the uPVC material
uPVC window production begins by compounding PVC resin powder with additives to create a rigid, weather-resistant plastic. The base resin is blended with a precise recipe of performance additives before it is ever extruded, and the quality of this recipe largely determines how long the finished window survives the sun.
- Base: unplasticised PVC (PVC-U) resin, typically 80-90 percent of the compound by weight
- Heat stabiliser: modern lines use lead-free calcium-zinc systems to prevent thermal degradation during extrusion
- UV stabiliser and pigment: titanium dioxide (TiO2) for whiteness and UV resistance, essential for the intense Indian sun
- Impact modifiers, lubricants and fillers (calcium carbonate) to improve toughness and processability
The dry-blended compound is mixed in high-speed mixers, cooled, and fed to the extruder as a free-flowing powder or granulate. Cheaper windows sometimes use higher filler loading or lead-based stabilisers, which is why insisting on lead-free, UV-stabilised compound matters so much in hot regions like Telangana. A titanium dioxide content of around 6-10 parts per hundred resin (phr) is a common benchmark for exterior-grade white profiles that must resist yellowing over a decade of Deccan sunshine.
Step 2: Extruding the multi-chamber profile
The compound is melted and forced through a shaped steel die to form a continuous hollow profile with internal air chambers. This extrusion step defines the window's cross-section, strength and thermal performance, and it is where the multi-chamber design that makes uPVC energy-efficient is created.
- Twin-screw extruders heat the compound to roughly 180-200 degrees C and push the molten PVC through a die shaped like the window cross-section
- The emerging profile is pulled through vacuum calibration and water-cooling tanks that lock in exact dimensions
- Standard frame profiles are 58-70 mm in system depth; 60 mm and 70 mm systems are the most common in India
- Profiles contain 2 to 5 internal chambers; more chambers trap more still air and improve thermal and acoustic insulation
- Outer wall thickness of 2.5-3.0 mm meets Class A per EN 12608, the grade recommended for hot, high-UV climates
The cooled profile is cut to stock lengths and, in most factories, wound with protective film before it goes to fabrication. A 5-chamber, 70 mm profile will noticeably outperform a 2-chamber, 58 mm profile on both heat gain and street noise, which is a real advantage on busy roads in central Hyderabad or near arterial corridors in Secunderabad.
Step 3: Cutting, steel reinforcement and drainage
Fabrication starts by cutting the profiles to length and inserting galvanised steel to give the plastic frame structural rigidity. uPVC alone is too flexible to carry wind and glazing loads on larger openings, so the hidden steel core is what keeps a large window straight and true over decades.
- Profiles are cut on precision saws to 45-degree mitres ready for welded corners
- Galvanised steel reinforcement, generally 1.5-2.0 mm thick, is screwed into the main chamber of frames and sashes
- Reinforcement is essential for wind-load resistance under IS 875 (Part 3) and for large or high-rise openings
- Drainage (weep) slots and hardware holes are routed or milled so rainwater drains outward rather than pooling
Correct steel sizing is critical in wind-exposed and high-rise Hyderabad and Secunderabad projects, where under-reinforced frames can bow or sag over time. For very large spans, sliding walls or commercial facades, many projects step up to an aluminium or hybrid system instead of uPVC; our team can advise when that is the smarter choice. You can review the full range of window and door options across our services to see where uPVC fits your project.
Step 4: Fusion welding the frame
The mitred profile ends are heated and fused together to form a single, seamless, airtight frame. This fusion weld is the defining strength of a quality uPVC window and uses no screws or brackets at the corners, which is precisely why welded frames stay sealed far longer than mechanically jointed alternatives.
- A welding machine presses the mitred ends against a heated plate at roughly 250-260 degrees C until the PVC softens
- The plate is withdrawn and the softened ends are pressed together, fusing into one continuous piece as they cool
- The result is a weatherproof, watertight corner with no mechanical joint that can loosen or leak
- Excess weld bead is trimmed and cleaned by corner-cleaning machines for a neat, uniform finish
Fusion-welded corners are why well-made uPVC frames stay airtight for decades, unlike mechanically screwed joints that can develop gaps. A quick way to inspect quality on site is to look at the corner weld line: it should be clean, continuous and free of voids or crumbly weld residue. If a fabricator uses screwed-and-cornered joints rather than true fusion welds, treat it as a red flag.
Step 5: Glazing, gaskets and drainage sealing
The welded frame is completed by fitting glass and sealing gaskets that lock out air and water. This is the stage that turns a bare frame into an insulated, weatherproof window, and the glass choice has a bigger effect on comfort and energy bills than most buyers expect.
- Glass is usually an insulated glazing unit (IGU): two panes separated by a 6-20 mm spacer filled with dry air or argon; single and laminated glass are also used
- Safety and toughened glass should conform to IS 2553 in relevant locations such as low-level glazing and doors
- EPDM or TPE rubber gaskets seal the glass-to-frame gap against air and water infiltration
- A completed double-glazed uPVC window typically delivers a U-value near 1.4-2.8 W/m2K, supporting ECBC and NBC 2016 energy goals
For homes on noisy roads, a double-glazed unit with an acoustic laminated pane can cut perceived street noise dramatically, while a solar-control or low-E coating reduces the heat that pours in during a Hyderabad summer. It is worth specifying the glass carefully rather than defaulting to the cheapest single glazing, because retrofitting better glass later costs far more than getting it right at manufacture. The same weatherproofing discipline carries over to uPVC doors fitted alongside your windows.
Step 6: Fitting locks, hinges and window hardware
Hardware is fitted last: multi-point locks, friction hinges and handles turn the sealed frame into a secure, operable window. In practice, the hardware makes or breaks how a window feels day to day and how long it stays smooth, so it deserves as much attention as the profile itself.
- Multi-point (espagnolette) locking pulls the sash tight against the frame at several points for security and a better seal
- Friction stays and hinges control casement opening and hold the sash at any angle in a breeze
- Handles, keeps and strikers complete the operating gear and should be corrosion-resistant for coastal Andhra Pradesh conditions
- Sliding windows run on stainless or nylon rollers sized to the sash weight for smooth, long-lasting operation
Quality gear from reputable hardware brands resists the humidity and grit of an Indian monsoon far better than generic parts. Cheap, unbranded hardware is the single most common reason a two-year-old window starts to stick, sag or rattle, so it is worth spending here even on an otherwise budget window. When you get a free quote, ask exactly which lock and hinge brands are included so you can compare like for like.
What uPVC windows cost in Hyderabad: an indicative price breakdown
Quality uPVC windows in Hyderabad and Secunderabad typically cost around INR 450-900 per sq ft supplied and fitted, with the final figure driven by profile depth, chamber count, glazing and hardware. The ranges below are indicative for the Telangana and Andhra Pradesh market and help you sanity-check any quote you receive.
- Economy (60 mm, 2-3 chamber, single glass, basic hardware): roughly INR 400-550 per sq ft
- Mid-range (70 mm, 3-5 chamber, double glazing, branded multi-point locks): roughly INR 600-800 per sq ft
- Premium (70 mm+, 5 chamber, laminated or low-E double glazing, upgraded hardware): roughly INR 850-1,200 per sq ft
- Add-ons: mosquito mesh shutters, grills, colour-laminated or woodgrain foil finishes, and toughened glass each add to the base rate
As a rule, sliding windows are usually cheaper per square foot than casement windows of the same specification, and larger fixed panels cost less than multiple operable sashes. Beware of quotes far below these ranges: they almost always signal thin Class B or C walls, missing or under-gauge steel, or unbranded hardware that will fail early. A written quote listing the system name, wall-thickness class, steel spec and glazing type lets you compare fairly.
Pros, cons and common mistakes to avoid
uPVC windows offer excellent insulation and near-zero maintenance, but they are only as good as the compound, steel and hardware inside them. Knowing the trade-offs and the usual buyer mistakes helps you get a window that performs for decades rather than years.
- Pros: superb thermal and acoustic insulation, no rot or corrosion, no repainting, good weather sealing, and low lifetime cost
- Cons: limited slim-sightline options versus aluminium, colour range narrower than powder-coated metal, and quality varies hugely between fabricators
- Mistake 1: choosing on price alone and ending up with thin-walled, unreinforced profiles that bow within a few summers
- Mistake 2: accepting single glazing where double glazing would have transformed comfort and noise for a modest extra cost
- Mistake 3: ignoring hardware brand, then living with sticking sashes and failing locks
- Mistake 4: poor installation, gaps left unsealed around the frame let water and noise straight past an otherwise good window
Even the best-made window underperforms if it is badly fitted, so choose a fabricator who both manufactures to standard and installs with proper packing, fixing and silicone sealing. Seeing a company's finished work, as in our recent projects, is a good way to judge installation quality before you commit.
Quality standards and what separates good uPVC from bad
The difference between a premium uPVC window and a cheap one comes down to compound quality, wall thickness, steel gauge and hardware, not the appearance out of the box. Two windows can look identical on day one and behave very differently after five monsoons.
- Wall thickness: Class A (2.5-3.0 mm) per EN 12608 is the benchmark for hot, high-UV climates; thinner Class B or C profiles flex and age faster
- Steel gauge: 1.5-2.0 mm galvanised reinforcement in the main chamber, present in both frame and sash on larger openings
- Weld quality: clean, continuous fusion welds with no gaps at the corners
- Compound: lead-free calcium-zinc stabiliser and adequate titanium dioxide for UV resistance
- Hardware: branded multi-point locks and hinges rather than generic gear
Ask any supplier for the profile system name, wall-thickness class and steel specification in writing. A reputable fabricator will happily provide these; a cheap one will change the subject. When in doubt, get a free quote that lists these details line by line so you can compare offers on a genuine like-for-like basis.
uPVC vs aluminium windows: which to choose in Hyderabad
Choose uPVC for the best thermal and acoustic insulation and lowest maintenance; choose aluminium for slim sightlines, very large spans and structural facades. Both perform well in Hyderabad's climate when made correctly, and the right pick depends on the opening size and look you want.
- Insulation: uPVC wins on U-value and noise reduction thanks to its multi-chamber, non-conductive profile
- Strength and spans: aluminium wins for large sliding walls, high-rise and facade work where slim, strong sections are needed
- Maintenance: both are low-maintenance; uPVC never needs painting, aluminium resists dents better
- Cost: quality uPVC in Hyderabad and Secunderabad runs around INR 450-900 per sq ft supplied and fitted, while premium aluminium systems often sit higher
For homes, apartments and quieter facades, uPVC windows and matching uPVC doors are usually the value choice. For shopfronts, large openings and facades, an aluminium or glass system is often better. Hakimi Aluminium and Glass fabricates and installs fusion-welded uPVC windows to the standards above across Hyderabad, Secunderabad and the wider Telangana and Andhra Pradesh region.
